Valid and precise quantification of clinical variables is essential for appropriate interpretation to inform healthcare decision making. The outcomes produced from different measurement procedures and instruments, purporting to quantify the same measurand, should be directly comparable. This ensures the appropriate application and widespread adoption of clinical research findings. Metrology provides a framework for the development of a common language of reference measurement systems, which have the potential to improve the accuracy and comparability of patients' results.However, the practices, procedures and instruments used in social measurement are currently excluded from any formal metrological framework. In this paper, we build on previous arguments, and propose a new international body to bring together metrology, psychometrics, philosophy, and clinical management to support the global comparability and equivalence of measurement results in patient centred outcome measurement to improve healthcare.